1. Field of the Invention
The present invention relates to an improvement in a body frame structure forming a skeletal structure of a vehicle.
2. Description of the Related Art
One example of conventional body frames of four-wheeled vehicles is shown in exploded perspective in FIG. 15 hereof. As seen from this figure, the body frame 200 includes principal skeletal members such as a front ceiling cross member 201, central ceiling cross member 202, rear ceiling cross member 203, front pillars 204, 204, center pillars 205, 205, rear pillars 206, 206, top longitudinal members 207, 207, bottom longitudinal members 208, 208 and intermediate members 209, 209, all of which have been obtained by cold punching and/or press bending metal plates.
The vehicle body frame 200 as assembled is shown in FIG. 16. The principal skeletal members, namely, front, center and rear ceiling cross members 201, 202, 203, front pillars 204, 204, center pillars 205, 205, rear pillars 206, 206, top longitudinal members 207, 207, bottom longitudinal members 208, 208 and intermediate members 209, 209 are connected together by spot welding or the like technique to form the body frame structure 200.
Since the skeletal members have hitherto been manufactured by cold punching metal plates, fragments or odd pieces have been produced, thus worsening the yield. Further, a large number of components or members have been required, because the skeletal structure has been formed by combining substantially linear members 201-209. This requires a multitude of man-hours for drafting drawings of, making plans for the manufacture of, manufacturing, temporarily assembling and welding the members, thus increasing the cost of manufacture of the body frame.